Stacking 825 on A7

[ngccglp]

Hi,

I am thinking of stacking a 825 cabs/515 to my existing A7 (I saw a brochure of the A6). Do I need to make a separate low pass filter or just tap the signal from my A7?

Also, I was thinking of removing the lower panels of the 825 to put the 511 into the cabs. Will the bass response of the 825 change significantly? I read that the A7 can be configured that way.

Thanks.

[GM]

Greets!

Yes it can: http://www.lansingheritage.org/image...ome/page02.jpg
http://www.lansingheritage.org/image...ome/page16.jpg

No, just wire them in parallel. When you say lower panels, with them upside down I recommend leaving off the narrow baffle board and mount the large one at the bottom of the cab (top) so you can mount the HF horn to the bottom (top) of the midbass horn to at least get it a little lower, unless you can sit far enough away for it not to be an issue, like >30-35ft.

Really, for a HI-FI app you should leave the A7 as is and space up the other cab like this: http://www.wmeckle.com/ALTEC/28.jpg

GM

[ngccglp]

Thanks GM,

I was thinking of making a spacer to support the 825 on top of the A7, but realized that it will hit the cornices of my ceiling. But if the horn is mounted inside, I will save some height. Someone is selling a pair of 825 cab at a good price, that was what prompted me to think about the A6 configuration, but actually your cabs will be ideal as far as height is concerned.

[GM]

Greets!

You're welcome!

Well, not mine, Bill Eckle built those for someone else and the owner ultimately used a HF Tractrix lens after giving up on trying to tweak a ~neutral 'sound' from the 311. You could shorten the 'new' 825 cabs just enough to clear the cornice boards and retune them so they match the floor mounted A7s.

Really, the horn is too high for HI-FI apps in a stock A7 so shortening/retuning all four would be my choice since these cabs are too big for probably 99% of the apps they're used in. There's far more gain to be had using 'wings' than the extra Vb.

GM